Air pollution alarm system adjusted

Shanghai adjusted its four-tier air pollution alarm system by lowering the criteria for alarm activation. Anti-pollution measures will be applied under stricter supervision.

A comparison of the adjusted and previous criteria.

Shanghai is to bring anti-pollution measures into play faster.

The city has adjusted its four-tier air pollution alarm system by lowering the criteria for alarm activation.

Furthermore, Shanghai Environmental Protection Bureau has pledged to issue alarms at least one day ahead of serious pollution occurring to enable citizens to better make preparations.

According to the new criteria, the lowest blue alarm will be activated when both slight pollution and short-term heavy pollution are forecast in the following 24 hours. Slight pollution is when the Air Quality Index is between 101 and 150, and short-term heavy pollution is when the AQI is over 200.

Previously, the blue alarm was issued when moderate pollution, with the AQI between 151 and 200, and short-term heavy pollution were predicted for the next 24 hours.

The second-level yellow alarm will now be issued when the AQI is forecast to be between 201 and 300 over the following 24 hours, down from 48 hours.

An orange alarm will be made when the AQI is predicted to be between 301 and 400, indicating heavy pollution, over the next 24 hours, or between 201 and 300 in the next two days — down from three days previously.

The criteria for the highest-level red alarm remains unchanged, triggered when the AQI is forecast to top 400, or severely polluted, in the next 24 hours.

Shou Ziqi, director of the environmental protection bureau, also said officials will try their utmost to bring forward the pollution alerts two or three days in advance from the current 24-hour prediction.

Zhang Yueying, principal of the Shanghai World Foreign Language Primary School, said she welcomes the new measures as they are good for children and helpful for schools to arrange teaching and activities.

“Air quality is one of the most important concerns for our teachers, students and parents. Whenever pollution happens, we take corresponding action, such as stopping outdoor activities under blue or yellow alerts and suspending classes under a red alert.”

Zhang added that she wished accurate and earlier alerts could be in place as the school had to cancel large-scale activities at the last minute, leaving students disappointed. As a result, the school tried to avoid arranging such activities during seasons when pollution was more likely.

“If we can see the alerts two or three days earlier, we can have more time to make rearrangements. We can book indoor spaces or alert guests about cancelations. And we can make an earlier decision whether outdoor spaces should be decorated and stages constructed, avoiding suffering an economic loss.”

The key priority, Zhang said, is to improve air quality.

Chen Yuhan, a student at Shanghai Minli Middle School, also expressed his wish for earlier alarms. “Every time there is a physical education class in the afternoon, I check the weather broadcasting information on TV in the morning.” But he still found PE classes suddenly canceled in the afternoon due to air pollution though the morning forecast showed the air quality suitable for physical exercise.

Shou of the environment bureau understands the frustrations.

The adjusted alarm criteria require more accurate work from the monitoring and forecasting department, he said, adding that anti-pollution measures under each alarm will generally remain the same but will be applied under stricter supervision to better control polluting sources.

When a blue alert is triggered, construction sites will be ordered to suspend open-air operations. Heavy industry factories, especially those discharging large amounts of volatile organic compounds, will be required to reduce waste discharge.

Under the orange alarm, medicine and furniture manufacturers will have their operations restricted or suspended.

Under red, electronic product companies and forging plants will be affected. Heavily polluting boats face being banned from using waterways, and schools and kindergartens will be closed.

Shou said the accuracy rate of Shanghai’s air quality forecast for the following 24 hours is about 80 percent.

“We are aware of citizens’ hopes of receiving earlier and more accurate forecasts. But accuracy is affected by complicated reasons, including changing meteorological conditions and limited technical methods.” Shanghai has put intense efforts into improving air quality forecasting in recent years, Shou added.

Shanghai, meanwhile, had its best year on the PM2.5 front since records of the yearly average density of the city’s major air pollution were begun five years ago. According to a report from the bureau, the average density of the hazardous-to-health tiny PM2.5 particles in 2017 dropped to 39 micrograms per cubic meter from 45 in 2016. The figure was 62 in 2013.

Also, Shanghai had nine months in 2017 with excellent or good air quality — with the AQI no higher than 100 — one month more than five years ago.

“The improvement has been obvious, but to maintain the result is not that easy,” said Shou. “We encourage citizens to use public transport more to lower the waste gas discharge from road traffic. The quality of oil products should also be improved.”

According to Shanghai’s anti-air pollution plan for the next three years, the yearly average density of PM2.5 should be lowered to 37mg per cubic meter by 2020. The figure should drop to 35 by 2022 to meet the national standard. To achieve that goal, Shou pledged stricter law enforcement will be applied against polluters. Frequent violators will see their company credit records affected.

“To put more effort on controlling polluting sources and apply a more detailed management system will be our major task regarding air quality improvement in the next three years,” Shou said.

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